The embodiments of the disclosure relate to the technical field of wireless communications, and particularly relate to a method, a system and a device for feeding back and receiving a Pre-coding Matrix Indicator (PMI), which is used for feeding back a vertical dimension PMI. The method for feeding back the PMI provided by the embodiments of the disclosure comprises: confirming the PMI needed to be fed back, wherein the PMI comprises a horizontal dimension PMI and a vertical dimension PMI, or a PMI combined by horizontal dimension and vertical dimension (801); feeding back the confirmed PMI in a non periodic Channel State Information (CSI) feedback mode or a periodic CSI feedback mode (802). Since the capability of feeding back the vertical dimension PMI, dynamic 3D beam shaping technology can be implemented and the throughput of the user equipments in the edge of cell and the average throughput can be improved.